<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width: 200px;
            height: 200px;
            background-color: red;
        }
    </style>
</head>
<body>
    <div class="box"></div>
    <script>
        const oBox = document.querySelector(".box")
        const fn = function(e){
            console.log(1);
            console.log(e);
            console.log(this);
        }
        const debounce=function(fn,wait){
            let t= null
            return function(e){
                if(t){
                    clearTimeout(t)
                }
                t = setTimeout(() => {
                    fn.call(this,e)
                }, wait);
            }
        }
        oBox.onmousemove=debounce(fn,300)
    </script>
</body>
</html>